\documentclass{article}

\usepackage{xparse}

\newlength{\boldAcrwidth}
\setlength{\boldAcrwidth}{2cm}

\ExplSyntaxOn
\cs_new_eq:NN \sctale_str_if_eq:nn \__str_if_eq:nn
\cs_generate_variant:Nn \sctale_str_if_eq:nn { oo }
\cs_new:Npn \__sctale_acro:w #1 \q_mark #2 \q_stop {#1}
\seq_new:N \l__sctale_acro_seq
\NewDocumentEnvironment { acroenv } { }
{ \seq_clear:N \l__sctale_acro_seq }
{
	\seq_sort:Nn \l__sctale_acro_seq
	{
		\int_compare:nNnTF
		{
			\sctale_str_if_eq:oo
			{ \__sctale_acro:w ##1 \q_stop }
			{ \__sctale_acro:w ##2 \q_stop }
		}
		< 0
		{ \sort_return_same: }
		{ \sort_return_swapped: }
	}
	\seq_map_function:NN \l__sctale_acro_seq \__sctale_put_acro:n
}
\cs_new:Npn \__sctale_put_acro:n #1 { \__sctale_put_acro:w #1 \q_stop }
\cs_new:Npn \__sctale_put_acro:w #1 \q_mark #2 \q_stop
{ \boldAcroPut{#1}{#2} }
\cs_new_eq:NN \dont \prg_do_nothing:
\NewDocumentCommand { \boldAcr }{ >{\SplitList{~}} m }
{
	\tl_set:Nx \l__sctale_tmpa_tl { \tl_map_function:nN {#1} \__sctale_make_acro:n }
	\seq_put_right:No \l__sctale_acro_seq { \l__sctale_tmpa_tl \q_mark {#1} }
}
\cs_new:Npn \__sctale_make_acro:n #1 { \__sctale_make_acro:w #1 \q_nil }
\cs_new:Npn \__sctale_make_acro:w #1 #2 \q_nil
{
	\token_if_eq_meaning:NNTF #1 \dont
	{ } { #1 }
}
\ExplSyntaxOff

\NewDocumentCommand{\boldAcroPut}{mm}{%
	\noindent
	\makebox[\boldAcrwidth][l]{\bfseries\textit{\MakeUppercase{#1}}}%
	\ProcessList{#2}{\boldAcrFirst}%
	\unskip\par%
}
\NewDocumentCommand{\boldAcrFirst}{m}{%
	\boldAcrFirstAux#1 % we want a space
}
\NewDocumentCommand{\boldAcrFirstAux}{m}{%
	\textbf{\MakeUppercase{#1}}%
}

\begin{document}

	\begin{acroenv}
		\boldAcr{open web application security project}
		\boldAcr{open web application security project}
	\end{acroenv}

\end{document}