title: Pilot-scale continuous pyrolysis of Pinus Radiatta sawdust

authors: Sichone, Kavwa

abstract: Lakeland Steel Limited developed a pilot plant for pyrolysing sawdust which proved successful in recent trials with sawdust and organic waste processing. Lakeland Steel was approached by a client to perform a preliminary economic assessment of a mobile sawdust pyrolysis unit. Feedstock properties such as proximate composition, elemental composition, calorific content, thermal decomposition reaction kinetics, and drying properties were determined. Pilot plant trials investigated the effects of processing parameters on product yields and properties. The parameters were feedstock moisture content at 15, 30 and 60%, reaction temperature at 400, 450 and 500°C and reactor auger speeds at 15, 20 and 25 rpm. Experiments at 60% moisture could not be performed to completion as the auger blocked repeatedly. The other two moisture contents showed that moisture content enhanced heat exchange properties of the feedstock and this generally increased the amount of volatile organic matter released. It was observed that for 15% moisture sawdust increase of temperature did not consistently exhibit an increase in degree of devolatilisation of organic matter. However, the 30% moisture sawdust showed an increase in devolatilisation with increase in temperature. The effects of increasing reactor auger speed had the most consistent trend with which an increase in speed showed a decrease in degree of devolatilisation thus increasing char yield.
A preliminary economic feasibility assessment was performed for the base case scenario which processed 29,000 tonnes/per year of green sawdust pre-dried to 15% moisture content at 400°C. The facility produced 5,250 tons biochar, 2,140 tons oil and 6,290 tons syngas per year. The syngas was recycled for heating and excess heat was also recovered from product cooling operations. However an additional 170 kg/hr. of natural gas was required to produce the required processing temperatures during start-up. The base case assessment was uneconomic, operating costs, including labour, were $1,200,000 per year and sales were $780,000 per year, assuming biochar could be sold for $150 per tonne. A sensitivity analysis showed that the process economics could be favourable assuming lower capital costs by eliminating the need for a rotary dryer and 50% reduction of labour costs by process automation. Provided that the char is sold at $150 per ton a payback period of four years can be achieved.

text: Pilot-scale continuous pyrolysis of Pinus Radiatta sawdust Lakeland Steel Limited developed a pilot plant for pyrolysing sawdust which proved successful in recent trials with sawdust and organic waste processing. Lakeland Steel was approached by a client to perform a preliminary economic assessment of a mobile sawdust pyrolysis unit. Feedstock properties such as proximate composition, elemental composition, calorific content, thermal decomposition reaction kinetics, and drying properties were determined. Pilot plant trials investigated the effects of processing parameters on product yields and properties. The parameters were feedstock moisture content at 15, 30 and 60%, reaction temperature at 400, 450 and 500°C and reactor auger speeds at 15, 20 and 25 rpm. Experiments at 60% moisture could not be performed to completion as the auger blocked repeatedly. The other two moisture contents showed that moisture content enhanced heat exchange properties of the feedstock and this generally increased the amount of volatile organic matter released. It was observed that for 15% moisture sawdust increase of temperature did not consistently exhibit an increase in degree of devolatilisation of organic matter. However, the 30% moisture sawdust showed an increase in devolatilisation with increase in temperature. The effects of increasing reactor auger speed had the most consistent trend with which an increase in speed showed a decrease in degree of devolatilisation thus increasing char yield.
A preliminary economic feasibility assessment was performed for the base case scenario which processed 29,000 tonnes/per year of green sawdust pre-dried to 15% moisture content at 400°C. The facility produced 5,250 tons biochar, 2,140 tons oil and 6,290 tons syngas per year. The syngas was recycled for heating and excess heat was also recovered from product cooling operations. However an additional 170 kg/hr. of natural gas was required to produce the required processing temperatures during start-up. The base case assessment was uneconomic, operating costs, including labour, were $1,200,000 per year and sales were $780,000 per year, assuming biochar could be sold for $150 per tonne. A sensitivity analysis showed that the process economics could be favourable assuming lower capital costs by eliminating the need for a rotary dryer and 50% reduction of labour costs by process automation. Provided that the char is sold at $150 per ton a payback period of four years can be achieved.

year: 2013

title: The effect of board characteristics on firm environmental performance

authors: de Villiers, Charl

subjects: middle managers

abstract: This article examines the strategic role of middle managers in the corporate entrepreneurial process from an attention-based perspective. By integrating literatures from multiple disciplines, the authors delineate the attention-based effects on how middle managers provide the impetus for different types of entrepreneurial opportunities (i.e., exploratory vs. exploitative initiatives). Specifically, middle managers, constrained by the attention structures of the firm, likely prescreen entrepreneurial opportunities from lower organizational levels and attend primarily to those that align with the strategic orientation of the firm. This tendency may be moderated by the presence of other players, middle managers’ structural positions, and the availability of slack resources. Moreover, in their efforts to sell initiatives to top management, middle managers may leverage “policy windows”—patterned regularities and irregularities in and around the organization—to exploit existing attention structures to their advantage or perhaps to dismantle those structures.

text: The effect of board characteristics on firm environmental performance This article examines the strategic role of middle managers in the corporate entrepreneurial process from an attention-based perspective. By integrating literatures from multiple disciplines, the authors delineate the attention-based effects on how middle managers provide the impetus for different types of entrepreneurial opportunities (i.e., exploratory vs. exploitative initiatives). Specifically, middle managers, constrained by the attention structures of the firm, likely prescreen entrepreneurial opportunities from lower organizational levels and attend primarily to those that align with the strategic orientation of the firm. This tendency may be moderated by the presence of other players, middle managers’ structural positions, and the availability of slack resources. Moreover, in their efforts to sell initiatives to top management, middle managers may leverage “policy windows”—patterned regularities and irregularities in and around the organization—to exploit existing attention structures to their advantage or perhaps to dismantle those structures.

year: 2011

title: Grounding the state of exception in New Zealand: A case study of racial segregation in Pukekohe, Whiteness and the Carceral State

authors: Martin, Jessica

subjects: State of exception

abstract: Indigenous scholars in settler-colonial contexts have highlighted the hyper-imprisonment of Indigenous people, locating it as an extension of the colonial project. Although research on this issue in New Zealand is emerging, there is a notable gap in understanding how the carceral state has developed within this particular context. This study aims to address the following research question: How does the historical context of racial segregation in Pukekohe contribute to our understanding of the mechanisms of the carceral state in New Zealand?
To thoroughly examine the hyper-imprisonment of Māori, it is essential to unpack the historical origins of state violence. Despite existing research establishing a link between Māori over-representation in prisons and the enduring effects of colonisation, there is a lack of studies exploring the complex interplay among the carceral state, whiteness, policy, policing, and law, which collectively shape the current landscape of incarceration. This study focuses on the racial segregation in Pukekohe between 1920 and 1960 and utilises reflexive thematic analysis within a case study framework, drawing on the insights offered by Robert Bartholomew's book, No Māori Allowed (2020). The analysis centres on the theoretical concept of the state of exception, shedding light on how power was wielded by the white racial polity. Thus, providing a unique perspective on the carceral state and state-sanctioned violence.
The findings highlight the interconnectedness of various systemic control mechanisms employed by the carceral state. Housing, policing, and whiteness emerge as crucial factors in the control and confinement of Māori in Pukekohe. By emphasising the role of whiteness in suppressing this history, this study underscores the need for critical examination and recognition of white cultural imperialism as a fundamental pillar of the carceral state. Overall, this research offers significant insights into the construction of a targeted population and the enduring consequences of state-sanctioned violence, emphasising the importance of a comprehensive examination of New Zealand's racialised history in discussions on the hyper-imprisonment of Māori.

text: Grounding the state of exception in New Zealand: A case study of racial segregation in Pukekohe, Whiteness and the Carceral State Indigenous scholars in settler-colonial contexts have highlighted the hyper-imprisonment of Indigenous people, locating it as an extension of the colonial project. Although research on this issue in New Zealand is emerging, there is a notable gap in understanding how the carceral state has developed within this particular context. This study aims to address the following research question: How does the historical context of racial segregation in Pukekohe contribute to our understanding of the mechanisms of the carceral state in New Zealand?
To thoroughly examine the hyper-imprisonment of Māori, it is essential to unpack the historical origins of state violence. Despite existing research establishing a link between Māori over-representation in prisons and the enduring effects of colonisation, there is a lack of studies exploring the complex interplay among the carceral state, whiteness, policy, policing, and law, which collectively shape the current landscape of incarceration. This study focuses on the racial segregation in Pukekohe between 1920 and 1960 and utilises reflexive thematic analysis within a case study framework, drawing on the insights offered by Robert Bartholomew's book, No Māori Allowed (2020). The analysis centres on the theoretical concept of the state of exception, shedding light on how power was wielded by the white racial polity. Thus, providing a unique perspective on the carceral state and state-sanctioned violence.
The findings highlight the interconnectedness of various systemic control mechanisms employed by the carceral state. Housing, policing, and whiteness emerge as crucial factors in the control and confinement of Māori in Pukekohe. By emphasising the role of whiteness in suppressing this history, this study underscores the need for critical examination and recognition of white cultural imperialism as a fundamental pillar of the carceral state. Overall, this research offers significant insights into the construction of a targeted population and the enduring consequences of state-sanctioned violence, emphasising the importance of a comprehensive examination of New Zealand's racialised history in discussions on the hyper-imprisonment of Māori.

year: 2024