Ingenieur Vol.82 April-June2020 | Page 74

INGENIEUR ‟“Systems thinking is a discipline for seeing wholes rather than parts, for seeing patterns of change rather than static snapshots, and for understanding the subtle interconnectedness that gives living systems their unique character” – Peter Senge author of The Fifth Discipline: The Art and Practice of the Learning Organization was shifted to the huge energy inefficiencies at the mills, which have led to greater than necessary amounts of the biomass residue being recycled into boiler furnaces - a practice that till today continues unaware and unrecognised. Meanwhile, money is slipping through the fingers. Owing to the ready supply of large amounts of waste oil palm MF and PKS right within the mill, without having to incur additional costs to transport and handle these resources, mill operators have enjoyed the luxury of generating copious amounts of steam while blatantly running their energy systems in an inefficient manner. This generous and ample steam supply has afforded a highly wasteful management of process steam. Systems thinking has helped in realising and understanding the various levels of energy inefficiencies present in palm oil mills. The exercise was useful in developing improved and new engineering designs and methods that are capable of significantly improving EE and reducing energy consumption at the mills. The innovation is capable of saving large amounts of biomass residue to improve profitability of palm oil production with a corresponding reduction in the carbon footprint of palm oil production, thereby improving its environmental sustainability – the target of palm oil’s harshest critics. Presently, palm oil mills are operating at extremely low EE levels, estimated at about 35-38%. This is a concern because it is tied to losses in valuable resource efficiency, an opportunity to reduce carbon emissions in the country and release RE potential. Energy consumption produces carbon dioxide (CO 2 ), which contributes to greenhouse gas (GHG) emissions. Unlocking potential EE and CO 2 savings requires projects that identify and eliminate energy waste. When and if this is achieved, a major portion (60%) of the biomass that is presently being consumed at the mill can be saved, thus maximising the economic value creation out of waste at the mills. Analysing energy and steam mass balance of palm oil mill processes systematically along with applying the principles of systems thinking has revealed several sources of energy waste that were initially invisible at the mills. Most significant was the inefficient use of process steam. Most of the energy used in palm oil milling is in the form of process heat supplied through process steam. A significant problem arises in practice because of a dichotomy - steam supply is regular whereas steam demand is irregular. In addition, the present sterilisation process design at the mill is such that it is difficult to avoid inefficient use of process steam due to ineffective evacuation of residual air from steriliser vessels. These factors lead to two negative outcomes: (1) large steam losses and (2) Combined heat and power (CHP) generation at the mill operating at far below its optimum potential. 72 VOL 82 APRIL-JUNE 2020