Cup Plant (Silphium perfoliatum L.) Biomass as Substitute for Expanded Polystyrene in Bonded Leveling Compounds

Lüders Moll,Martin Höller,Christoph A C Korte,Christian Wever,Charlotte Hubert,Ralf Pude,Georg Völkering

doi:10.3390/agronomy12010178

Abstract

Biomass for non-food applications is considered as a substitute for petro-based materials such as expanded polystyrene (EPS). This research analyzes physical properties of an EPS containing commercial bonded leveling compound (BLC) which was substituted with cup plant (Silphium perfoliatum L.) biomass. Cup plant is a high-yielding biomass plant with several ecological benefits that is yet mainly used for biogas production. Furthermore, the high amount of parenchyma in senescent biomass with its EPS-like structure could be a possible substitute for petrochemical foams in lightweight aggregates. The natural variation in parenchyma content of several European cup plant accessions is promising, regarding the development of cultivars with suitable biomass properties for the proposed material use. Two binders with different proportions of cup plant and EPS were used to produce samples of BLC for thermal conductivity and compression strength tests. The compression strength of 0.92 N mm−2 and a thermal conductivity of 84 mW m−1 K−1 were analyzed and comparable to the commercial BLC. The thermal conductivity within the tested borders appears nearly independent of the biomass content. With increasing cup plant content, the shape characteristics of the lightweight aggregate mix changes towards more elongated aggregates. The mechanical strength and thermal conductivity are highly sensitive to the water demand of the biomass. Direct partial substitution of EPS by cup plant appears feasible and could be a part of the decarbonization of the construction sector.

Highlights

Introduction published maps and institutional affilBuilding and construction materials are responsible for 11% of global annual greenhouse gas emissions, and building operations are adding a further 28% [1]
It was examined if expanded polystyrene (EPS) can be substituted by cup plant aggregates and if adverse biomass effects can be reduced by changing the binder
Neroth et al assume that pores have to be to be closed as as small as possible low thermal conductivity

Summary

Introduction

Building and construction materials are responsible for 11% of global annual greenhouse gas emissions, and building operations are adding a further 28% [1]. This industrial sector becomes an integral element of battling climate change. Cup plant (Silphium perfoliatum L.) is an undomesticated wild crop [12] with a dry matter yield of 14–25 Mg ha−1 y−1 [13], if harvested in August for biogas production or of 8.4–14.3 Mg ha−1 y−1 in case of harvesting in December as a raw material for building materials [11] This perennial crop can be harvested annually for a period of 15–20 years

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