LIFE CYCLE ANALYSIS (GATE TO GATE APPROACH) OF DIFFERENT LIGNOCELLULOSIC BIOMASS WASTE FOR PULPING OPERATIONS

Abstract

Paper and paper based packaging have seen a massive increase in demand in the past few years leading to acceleration in deforestation rate to meet the increasing demand which has negatively impacted the environment. There is a need to look towards non-woody lignocellulosic biomass to ease the burden on woody based materials. Wheat straw is waste product produced during wheat cultivation which is a common grown crop around the world abundant in cellulose and having minimal lignin present in them making them suitable for paper making. The main reason behind using these is their fast annual growth along with obtaining Wheat Straw (WS) as a byproduct which is a waste that can be utilized for papermaking. Another lignocellulosic biomass of interest is Sugarcane Bagasse (SB) which is considered a like for like replacement for woody based materials. Banana pseudostem (BSP) which is a waste material left for rotting after bearing fruit as banana only bears fruit once in its lifetime holds higher potential for utilization as a starting material for pulping due to it being rich in cellulose and being lean in lignin.. Kraft pulping is a commonly used method of pulping which involves input parameters like dose, temperature and time which needs to be optimized. Generally for making writing and printing paper, the pulp used has kappa number 15, which is considered as target value for pulping. A combined effect of One Factor at a time (OFAT) analysis and orthogonal array Design of Experiments (DoE) is conducted for targeted kappa number pulping. Energy based calculations are done to determine which lignocellulosic biomass out of the chosen three consumes the maximum energy followed by conducting Life cycle Assessment (LCA) using the Open-LCA software to understand the negative environmental impacts on human health, ecosystem quality and resource depletion of all the three material production route for producing kappa number 15 pulp. WS pulping has most negative impact on environment while SB pulping method is the most energy consuming process. Mechanical Paper properties are estimated which show that BPS has the maximum strength properties which suggest that this material can potentially be used for pulping to mitigate the raw material crisis and for potentially making products like wrapping and packing paper. The industry can use this study to identify the pulping parameters for any targeted kappa number value at which the maximum yield value is obtained. Additionally, the black liquor calorific value for each material is calculated and the banana pseudostem has the highest value which can further be used for thermal upgradation for better utilization as a fuel.