Business Ethics, Corporate Philosophy and Regulatory Challenges in the Confectionary Industry: An Evaluation of the Bread Market in Nigeria

This study sets out to identify why - in the process of “doing business”- most organizations in Nigeria resort to offering sub standard products to the public, particularly as regards food products. This approach allows businesses to make excess profit without recourse to best ethical practices, the supposed corporate philosophy of their organizations, and to the detriment of the customers. Indiscriminate profit maximization” mentality is now on the increase within the confectionary industry in Nigeria; thus the paper considered the theory of public interest and gives an insight to Kant’s ethical philosophy with a view to critically evaluate the role of The National Agency for Food and Drug Administration and Control (NAFDAC); the agency charged with the responsibility of upholding best ethical practices among confectionary and related industries in Nigeria. The study also identified some lapses in the discharge of NAFDAC’s regulatory functions which have contributed to the incidence of unethical practices among Nigerian business organisations. The paper therefore recommends that NAFDAC operations be re-evaluated for better operational performanc

Industrial waste-heat recovery through integrated computer-aided working-fluid and ORC system optimisation using SAFT-Γ Mie

A mixed-integer non-linear programming optimisation framework is formulated and developed that combines a molecular-based, group-contribution equation of state, SAFT-γ Mie, with a thermodynamic description of an organic Rankine cycle (ORC) power system. In this framework, a set of working fluids is described by its constituent functional groups (e.g., since we are focussing here on hydrocarbons: –CH3, –CH2–, etc.), and integer optimisation variables are introduced in the description the working-fluid structure. Molecular feasibility constraints are then defined to ensure all feasible working-fluid candidates can be found. This optimisation framework facilitates combining the computer-aided molecular design of the working fluid with the power-system optimisation into a single framework, thus removing subjective and pre-emptive screening criteria, and simultaneously moving towards the next generation of tailored working fluids and optimised systems for waste-heat recovery applications. SAFT-γ Mie has not been previously employed in such a framework. The optimisation framework, which is based here on hydrocarbon functional groups, is first validated against an alternative formulation that uses (pseudo-experimental) thermodynamic property predictions from REFPROP, and against an optimisation study taken from the literature. The framework is then applied to three industrial waste-heat recovery applications. It is found that simple molecules, such as propane and propene, are the optimal ORC working fluids for a low-grade (150 °C) heat source, whilst molecules with increasing molecular complexity are favoured at higher temperatures. Specifically, 2-alkenes emerge as the optimal working fluids for medium- and higher-grade heat-sources in the 250–350 °C temperature range. Ultimately, the results demonstrate the potential of this framework to drive the search for the next generation of ORC systems, and to provide meaningful insights into identifying the working fluids that represent the optimal choices for targeted applications. Finally, the effects of the working-fluid structure on the expander and pump are investigated, and the suitability of group-contribution methods for evaluating the transport properties of hydrocarbon working-fluids are considered, in the context of performing complete thermoeconomic evaluations of these systems

Computer-aided working-fluid design, thermodynamic optimisation and technoeconomic assessment of ORC systems for waste-heat recovery

The wider adoption of organic Rankine cycle (ORC) technology can be facilitated by improved thermodynamic performance and reduced costs. In this context the power system should be evaluated based on a thermeconomic assessment with the aim of improving economic viability. This paper couples the computer- aided molecular design (CAMD) of the working-fluid with thermodynamic modelling and optimisation, in addition to heat-exchanger sizing models, component cost correlations, and a thermoeconomic assessment. The proposed CAMD-ORC framework, based on the SAFT-γ Mie equation of state, allows the thermodynamic optimisation of the cycle and working-fluid in a single stage, thus removing subjective and pre-emptive screening criteria that would otherwise exist in conventional studies. Following validation, the framework is used to identify optimal working-fluids for three different heat sources (150, 250 and 350 °C), corresponding to small- to medium-scale applications. In each case, the optimal combination of working-fluid and ORC system is identified, and investment costs are evaluated. It is observed that fluids with low specific-investment costs (SIC) are different to those that maximise power output. The fluids with the lowest SIC are isoheptane, 2-pentene and 2-heptene, with SICs of 5,620, 2,760 and 2,070 £/kW respectively, and corresponding power outputs of 32.9, 136.6 and 213.9 kW

Experimental Investigation of the Operating Point of a 1-kW ORC System

The organic Rankine cycle (ORC) is a promising technology for the conversion of waste heat from industrial processes as well as heat from renewable sources. Many efforts have been channeled towards maximizing the thermodynamic potential of ORC systems through the selection of working fluids and the optimal choice of operating parameters with the aim of improving overall system designs, and the selection and further development of key components. Nevertheless, experimental work has typically lagged behind modelling efforts. In this paper, we present results from tests on a small-scale (1 kWel) ORC engine consisting of a rotary-vane pump, a brazed-plate evaporator and a brazed-plate condenser, a scroll expander with a built-in volume ratio of 3.5, and using R245fa as the working fluid. An electric oil-heater acted as the heat source, providing hot oil at temperatures in the range 120-140°C. The frequency of the expander was not imposed by an inverter or the electricity grid but depended directly on the attached generator load; both the electrical load on the generator and the pump rotational speed were varied in order to investigate the performance of the system. Based on the generated data, this paper explores the relationship between the operating conditions of the ORC engine and changes in the heat-source temperature, pump and expander speeds leading to working fluid flow rates between 0.0088 kg/s and 0.0337 kg/s, from which performance maps are derived. The experimental data is, in turn, used to assess the performance of both the individual components and of the system, with the help of an exergy analysis. In particular, the exergy analysis indicates that the expander accounts for the second highest loss in the system. Analysis of the results suggests that increased heat-source temperatures, working-fluid flow rates, higher pressure ratios and larger generator loads improve the overall cycle efficiency. Specifically, a 46% increase in pressure ratio from 2.4 to 4.4 allowed a 3-fold electrical power output increase from 180 W to 550 W, and an increase in the thermal efficiency of the ORC engine from 1 to 4%. Beyond reporting on important lessons learned in improving the performance of the system under consideration, comparisons will be shown for making proper choices with respect to the interplay between heat-source temperature, generator load, and pump speed in an ORC system

Useful Energy From Wasted Heat

Recent decades have seen an ever-increasing interest in the utilization of renewable and sustainable energy sources such as wind, solar, and biomass amongst other solutions, as well as in improving energy efficiency in the residential and commercial sectors through a wide variety of solutions

Intermittent waste heat recovery via ORC in coffee torrefaction

Coffee torrefaction is carried out by means of hot air at average temperature of 200-240°C and with intermittent cycles where a lot of heat is discharged from the stack. CHP systems have been investigated to provide heat to the process. However, much of the heat released in the process is from the afterburner that heats up the flue gas to higher temperatures to remove volatile organic compounds and other pollutants. In this paper, the techno-economic feasibility of utilising waste heat from a rotating drum coffee roasting with partial hot gas recycling is assessed. A cost analysis is adopted to compare the profitability of two systems configurations integrated into the process. The case study of a major coffee torrefaction firm with 500 kg/hr production capacity in the Italian energy framework is taken. The CHP options under investigation are: (i) regenerative topping micro gas turbine (MGT) coupled to the existing modulating gas burner to generate hot air for the roasting process; (ii) intermittent waste heat recovery from the hot flue gas through an organic Rankine cycle (ORC) coupled to a thermal storage buffer. The results show that the profitability of these investments is highly influenced by the natural gas/electricity cost ratio, by the coffee torrefaction production capacity and intermittency level of discharged heat. In this case study, MGT seems to be more profitable than waste heat recovery via ORC due to the intermittency of the heat source and the relatively high electricity/heat cost ratio